Combustion control system of double-hearth boiler

Abstract

The utility model provides a combustion control system for a double-hearth boiler, which is characterized in that each hearth is provided with a combustion head, and the control system comprises a combustion controller, a guide fire pipeline, a main fire pipeline, a gas valve group, a rectifying unit, a first flame detector, a second flame detector, a first ion probe and a second ion probe, the combustion controller, the rectifying unit, the first flame detector and the second flame detector are connected in series to form a control loop, the first flame detector is connected with the first ion probe, the second flame detector is connected with the second ion probe, the first ion probe is installed in one hearth, and the second ion probe is installed in the other hearth. The second ion probe is installed in the other hearth, the combustion controller is configured to be capable of controlling the gas valve set to act so that the guide fire pipeline can be connected, and the combustion controller is further configured to be capable of controlling the gas valve set to act so that the main fire pipeline can be connected and the guide fire pipeline can be closed. According to the invention, the design of the boiler with higher power requirement is realized through a double-hearth combustion control mode.

Description

Technical Field

[0001] The utility model relates to the field of boilers, in particular to a combustion control system for a double-furnace boiler. Background Art

[0002] Generally speaking, one boiler often corresponds to one furnace, and the power of the boiler is limited by the power of the burner. For a fully premixed combustion system, there is a certain premixing space. The greater the power, the greater the premixing space required, and the higher the corresponding safety requirements. Therefore, the power of the more mature burners is not large, generally around 2800KW. Utility Model Content

[0003] In order to solve the technical problems existing in the prior art, the utility model discloses a double-furnace boiler combustion control system, and the specific technical scheme is as follows:

[0004] The present invention provides a combustion control system for a double-furnace boiler, each furnace is equipped with a combustion head, and the control system comprises a combustion controller, a pilot fire pipeline, a main fire pipeline, a gas valve group, a rectifier unit, a first flame detector, a second flame detector, a first ion probe and a second ion probe.

[0005] The combustion controller, the rectifier unit, the first flame detector and the second flame detector are connected in series to form a control loop, the first flame detector is connected to the first ion probe, the second flame detector is connected to the second ion probe, the first ion probe is installed in one of the furnaces, and the second ion probe is installed in the other furnace, the combustion controller is configured to control the gas valve group to connect the pilot fire pipeline, and the combustion controller is also configured to control the gas valve group to connect the main fire pipeline and close the pilot fire pipeline;

[0006] When ignition starts, the combustion controller controls the gas valve group to connect the pilot fire pipeline. When the first ion probe detects the flame signal of one of the furnaces, the first flame detector is closed. When the second ion probe detects the flame signal of another furnace, the second flame detector is closed. At this time, the control loop formed by the combustion controller, the rectifier unit, the first flame detector and the second flame detector is connected. The rectifier unit outputs a rectifier signal. The combustion controller determines whether the combustion head is in operation based on the received rectifier signal. If the combustion controller receives the rectifier signal, the combustion controller controls the gas valve group to connect the main fire pipeline, close the pilot fire pipeline, and the main fire is ignited successfully.

[0007] Further, if the combustion controller does not receive the rectification signal, the combustion controller controls the pilot fire pipeline to be closed, or the combustion controller controls the main fire pipeline to be closed.

[0008] Furthermore, one end of the main fire pipeline is the inlet end for air and gas, the other end of the main fire pipeline is connected to the combustion head, one end of the guide fire pipeline is the inlet end for gas, the other end of the guide fire pipeline is connected to the guide fire igniter, the guide fire igniter is arranged in the furnace or on the surface of the combustion head, and the first ion probe and the second ion probe are respectively close to the guide fire igniter.

[0009] Furthermore, it also includes a fan, which is connected to one end of the main fire pipeline, and the fan delivers air into the combustion head through the inlet end of the main fire pipeline.

[0010] Further, the gas valve group includes a first gas valve V1, a second gas valve V2 and a pilot fire ignition valve Pv, the first gas valve V1, the second gas valve V2 and the pilot fire ignition valve Pv are electrically connected to the combustion controller respectively, the first gas valve V1 and the second gas valve V2 are arranged on the main fire pipeline, the pilot fire ignition valve Pv is arranged on the pilot fire pipeline, the first gas valve V1 and the pilot fire ignition valve Pv are connected in series to form a pilot fire pipeline and then connected to the furnace, the first gas valve V1 and the second gas valve V2 on the main fire pipeline are connected in series to form a main gas pipeline and then connected to the furnace,

[0011] During ignition, the combustion controller is configured to control the first gas valve V1 and the pilot fire ignition valve Pv to open, the pilot fire pipeline is connected, and when the first ion probe detects a flame signal from one of the furnaces, the first flame detector is closed, and when the second ion probe detects a flame signal from another furnace, the second flame detector is closed. At this time, the control loop formed by the combustion controller, the rectifier unit, the first flame detector and the second flame detector is connected, and the rectifier unit outputs a rectifier signal. The combustion controller determines whether the combustion head is in operation based on the received rectifier signal. If the combustion controller receives a rectifier signal, the combustion controller is configured to control the second gas valve V2 to open, and the combustion controller controls the pilot fire ignition valve Pv to close after a certain delay, and the main fire is ignited successfully. If the combustion controller does not receive a rectifier signal, the combustion controller controls the first gas valve V1 and the pilot fire ignition valve Pv to close, or the combustion controller controls the first gas valve V1 and the second gas valve V2 to close.

[0012] Furthermore, if the combustion controller does not receive the rectification signal, the combustion controller controls the first gas valve V1 and the pilot fire ignition valve Pv to close, or the combustion controller controls the first gas valve V1 and the second gas valve V2 to close, then the ignition fails, and the combustion controller alarms and self-locks and saves the ignition failure record.

[0013] Furthermore, it also includes a shell, the double furnaces are located in the shell, a heat exchange shell is arranged in the shell, a heat exchanger is arranged outside each combustion head, and two heat exchangers are arranged in the heat exchange shell.

[0014] Furthermore, the first flame detector and the second flame detector are both flame relays.

[0015] Furthermore, the combustion controller includes a flame detection contact, the rectifier unit includes a capacitor, a resistor, a diode and a resistor, one end of the diode is connected to the flame detection contact, the other end of the diode is connected in series with one end of the resistor, the other end of the resistor is connected in series with the first flame detector and the second flame detector, and the capacitor is connected in parallel with the diode.

[0016] Furthermore, the rectifier unit is also provided with a status indicator light and a test button.

[0017] The utility model has the following beneficial effects:

[0018] (1) The dual-furnace boiler combustion control system of the utility model effectively integrates the burner. The dual-furnace combustion only requires one set of combustion controller, one set of gas valve group and one fan. Compared with the modular design structure, the combustion system in the boiler has a simple structure and reduces the production cost.

[0019] (2) The dual-furnace boiler combustion control system of the present invention can conveniently integrate the existing single burner to double the combustion power and meet the demand for boiler power expansion.

[0020] (3) The dual-furnace boiler combustion control system of the utility model has a certain degree of versatility and is compatible with most burners currently on the market, without the need to modify the design of the existing burner control unit.

[0021] (4) The dual-furnace boiler combustion control system of the utility model is equipped with a one-touch test button, which can perform functional testing on the rectifier unit at any time, facilitating inspection and maintenance.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 This is the block diagram of the combustion control system of the double-furnace boiler of the utility model. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal connection between two elements or interaction between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] See also Figure 1. The utility model provides a combustion control system for a double-furnace boiler, each furnace is equipped with a burner head, and the control system includes a combustion controller, a pilot fire pipeline, a main fire pipeline, a gas valve group, a rectifier unit, a first flame detector, a second flame detector, a first ion probe and a second ion probe. The combustion controller is configured to control the gas valve group to connect the pilot fire pipeline, and the combustion controller is also configured to control the gas valve group to connect the main fire pipeline and close the pilot fire pipeline. An accommodating cavity is formed on the inner side of the heat exchanger, and the accommodating cavity is the furnace, and the burner head is installed in the furnace.

[0029] The combustion controller, the rectifier unit, the first flame detector and the second flame detector are connected in series to form a control loop, the first flame detector is connected to the first ion probe, the second flame detector is connected to the second ion probe, the first ion probe is installed in one of the furnaces, and the second ion probe is installed in the other furnace. Further, the combustion controller includes a flame detection contact, and the flame detection contact, the rectifier unit, the first flame detector and the second flame detector are connected in series to form a control loop. Further, the first flame detector and the second flame detector are both flame relays. The first ion probe and the second ion probe are both flame probes, which are used to detect whether there is flame burning in the furnace.

[0030] When ignition starts, the combustion controller controls the gas valve group to operate so that the pilot fire pipeline is connected. When the first ion probe detects the flame signal of one of the furnaces, the first flame detector is closed. When the second ion probe detects the flame signal of another furnace, the second flame detector is closed. At this time, the control loop formed by the combustion controller, the rectifier unit, the first flame detector and the second flame detector is connected. The rectifier unit outputs a rectifier signal. The combustion controller determines whether the combustion head is in operation according to the received rectifier signal. If the combustion controller receives the rectifier signal, the combustion controller controls the gas valve group to operate so that the main fire pipeline is connected, the pilot fire pipeline is closed, and the main fire is ignited successfully. In one embodiment, if the combustion controller does not receive the rectifier signal, the combustion controller controls the pilot fire pipeline to be closed, or the combustion controller controls the main fire pipeline to be closed.

[0031] The control system also includes a fan. The main fire pipeline is a main air-gas pipeline. One end of the main fire pipeline is the inlet end for air and gas, and the other end of the main fire pipeline is connected to the burner head. The fan is connected to one end of the main fire pipeline, and the fan delivers air into the burner head through the inlet end of the main fire pipeline. The main fire pipeline is provided with a first gas valve V1 and a second gas valve V2, and the fan delivers air into the burner head through one end of the main fire pipeline, and the gas enters the burner head from one end of the main fire pipeline after passing through the first gas valve V1 and the second gas valve V2. One end of the pilot fire pipeline is the inlet end for gas, and the other end of the pilot fire pipeline is connected to a pilot fire igniter, and the pilot fire igniter is provided in the furnace or on the surface of the burner head. The first ion probe and the second ion probe are respectively close to the pilot fire igniter, and the gas is delivered from the pilot fire pipeline into the burner head through the first gas valve V1 and the pilot fire ignition valve Pv.

[0032] The gas valve group includes a first gas valve V1, a second gas valve V2 and a pilot fire ignition valve Pv, which are electrically connected to the combustion controller respectively, and the first gas valve V1 and the second gas valve V2 are arranged on the main fire pipeline, and the pilot fire ignition valve Pv is arranged on the pilot fire pipeline. The first gas valve V1 and the pilot fire ignition valve Pv are connected in series to form a pilot fire pipeline and then connected to the furnace, and the first gas valve V1 and the second gas valve V2 on the main fire pipeline are connected in series to form a main gas pipeline and then connected to the furnace.

[0033] Specifically, after the boiler system is started, after the combustion system is ready before ignition, the high-voltage ignition device starts to ignite, and the combustion controller controls the opening of the first gas valve V1 and the pilot fire ignition valve Pv. At this time, the pilot fire pipeline is connected, and the second gas valve V2 is closed. At this time, the first ion probe is used to detect whether there is a flame in one of the furnaces or on the surface of the burner head. When the first ion probe detects a flame signal in the furnace or on the surface of the burner head, the first flame detector is closed. The second ion probe is used to detect whether there is a flame in another furnace or on the surface of the burner head. When the second ion probe detects a flame signal in another furnace or on the surface of the burner head, the second flame detector is closed. At this time, the flame detection contacts of the combustion controller, The control loop composed of the rectifier unit, the first flame detector and the second flame detector is connected, and the rectifier unit outputs a rectifier signal to the combustion controller. The combustion controller determines whether the combustion head is in operation according to the received rectifier signal. If the combustion controller receives the rectifier signal, the combustion head is in the ignition operation state. In this stage, the control loop operates stably, and the combustion controller controls the second gas valve V2 to open, and the combustion controller controls the pilot ignition valve Pv to close after a certain delay. When the pilot ignition valve Pv is closed and the first gas valve V1 and the second gas valve V2 are opened, if the control loop continues to maintain a stable operation state, it means that the double furnace combustion head is ignited successfully, and the boiler will operate normally thereafter. If the combustion controller does not receive the rectifier signal when the first gas valve V1 and the pilot ignition valve Pv are open, or the combustion controller does not receive the rectifier signal when the first gas valve V1 and the second gas valve V2 are open, the combustion controller controls the gas valve group to close, which means that the ignition has failed. The combustion controller alarms and self-locks and saves the ignition failure record.

[0034] In one embodiment, the control system further comprises a shell, a heat exchange shell is arranged inside the shell, two furnaces are located inside the shell, each furnace is equipped with a burner head, and each furnace is equipped with an independent ignition and flame detector. A heat exchanger is arranged outside each burner head, and two heat exchangers are arranged in the heat exchange shell. After the gas is burned in the two furnaces, the high-temperature flue gas generated by the combustion flows to the outside of the heat exchanger after heat exchange in the heat exchanger. The two heat exchangers share a heat exchange shell, and the high-temperature flue gas is discharged through the smoke port of the shell after heat exchange in the heat exchanger.

[0035] The rectifier unit includes a capacitor, a resistor, a diode and a resistor. One end of the diode is connected to the flame detection contact of the combustion controller, the other end of the diode is connected in series with one end of the resistor, the other end of the resistor is connected in series with the first flame detector and the second flame detector, and the capacitor is connected in parallel with the diode. The rectifier unit is also provided with a status indicator and a test button. By utilizing the rectifying function of the diode on the alternating current, a direct current signal that meets a certain signal strength requirement is obtained. The flame detection unit is two flame relays. After detecting the flame signal, the flame relay will provide a closing signal to close the circuit loop connected in series with the rectifier unit. At this time, the control loop composed of the combustion controller, the rectifier unit, the first flame detector and the second flame detector is connected. The rectifier signal of the rectifier unit is fed back to the combustion controller through the control loop. The rectifier signal emitted by the rectifier unit reflects the operating state of the combustion head, and the combustion controller obtains the operating state signal of the combustion head. If one of the combustion heads stops running, the corresponding flame relay outputs a circuit-breaking signal. At this time, the control circuit of the sorting unit is disconnected, and the operating state signal of the combustion head cannot be fed back to the combustion controller, so that the combustion controller will judge that the combustion head is in a non-operating state at this time, and the combustion controller controls the gas valve group to close. In order to facilitate simple and convenient operation and maintenance by operators, a status indicator light and a test button are provided inside the rectifier unit. The status indicator light is green after power-on. When the rectifier unit is operating normally, that is, when the two furnaces are ignited at the same time, the status indicator light is red. During the maintenance stage of the control system, press the test button. If the status indicator light is orange, it means that the internal circuit of the rectifier unit is normal.

[0036] The combustion control system of the utility model has the following beneficial effects:

[0037] (1) The utility model realizes the boiler design with higher power requirements through a dual-furnace combustion control method, which effectively integrates the combustion head. The dual-furnace combustion only requires a set of combustion controllers, a set of gas valve groups and a fan. Compared with the modular design structure, the combustion system in the boiler has a simple structure and reduces the production cost.

[0038] (2) The utility model can conveniently integrate the existing single burner to double the combustion power and meet the demand for boiler power expansion.

[0039] (3) The utility model has a certain degree of versatility and is compatible with most burners currently on the market, without the need to modify the design of the existing burner control unit.

[0040] (4) The utility model is equipped with a one-touch test button, which can perform functional testing on the rectifier unit at any time, making it easy to overhaul and maintain.

[0041] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0042] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify and vary the above embodiments within the scope of the present invention.

Claims

1. A combustion control system for a double-furnace boiler, each furnace is equipped with a combustion head, characterized in that: The control system includes a combustion controller, a pilot fire pipeline, a main fire pipeline, a gas valve group, a rectifier unit, a first flame detector, a second flame detector, a first ion probe and a second ion probe. The combustion controller, the rectifier unit, the first flame detector and the second flame detector are connected in series to form a control loop, the first flame detector is connected to the first ion probe, the second flame detector is connected to the second ion probe, the first ion probe is installed in one of the furnaces, and the second ion probe is installed in the other furnace, the combustion controller is configured to control the gas valve group to connect the pilot fire pipeline, and the combustion controller is also configured to control the gas valve group to connect the main fire pipeline and close the pilot fire pipeline; When ignition starts, the combustion controller controls the gas valve group to connect the pilot fire pipeline. When the first ion probe detects the flame signal of one of the furnaces, the first flame detector is closed. When the second ion probe detects the flame signal of another furnace, the second flame detector is closed. The control loop formed by the combustion controller, the rectifier unit, the first flame detector and the second flame detector is connected. The rectifier unit outputs a rectifier signal. The combustion controller determines whether the combustion head is in operation based on the received rectifier signal. If the combustion controller receives the rectifier signal, the combustion controller controls the gas valve group to connect the main fire pipeline, the pilot fire pipeline is closed, and the main fire is ignited successfully.

2. The double-furnace boiler combustion control system according to claim 1, characterized in that: If the combustion controller does not receive the rectification signal, the combustion controller controls the pilot fire pipeline to be closed, or the combustion controller controls the main fire pipeline to be closed.

3. The double-furnace boiler combustion control system according to claim 1, characterized in that: One end of the main fire pipeline is the inlet end for air and gas, and the other end of the main fire pipeline is connected to the burner head. One end of the pilot fire pipeline is the inlet end for gas, and the other end of the pilot fire pipeline is connected to the pilot fire igniter. The pilot fire igniter is arranged in the furnace or on the surface of the burner head, and the first ion probe and the second ion probe are respectively close to the pilot fire igniter.

4. The double-furnace boiler combustion control system according to claim 1, characterized in that: It also includes a fan, which is connected to one end of the main fire pipeline. The fan delivers air into the combustion head through the inlet end of the main fire pipeline.

5. The double-furnace boiler combustion control system according to claim 3, characterized in that: The gas valve group includes a first gas valve V1, a second gas valve V2 and a pilot fire ignition valve Pv, the first gas valve V1, the second gas valve V2 and the pilot fire ignition valve Pv are electrically connected to the combustion controller respectively, the first gas valve V1 and the second gas valve V2 are arranged on the main fire pipeline, the pilot fire ignition valve Pv is arranged on the pilot fire pipeline, the first gas valve V1 and the pilot fire ignition valve Pv are connected in series to form a pilot fire pipeline and then connected to the furnace, the first gas valve V1 and the second gas valve V2 on the main fire pipeline are connected in series to form a main gas pipeline and then connected to the furnace, During ignition, the combustion controller is configured to control the first gas valve V1 and the pilot fire ignition valve Pv to open, the pilot fire pipeline is connected, and when the first ion probe detects a flame signal from one of the furnaces, the first flame detector is closed, and when the second ion probe detects a flame signal from another furnace, the second flame detector is closed. At this time, the control loop formed by the combustion controller, the rectifier unit, the first flame detector and the second flame detector is connected, and the rectifier unit outputs a rectifier signal. The combustion controller determines whether the combustion head is in operation based on the received rectifier signal. If the combustion controller receives a rectifier signal, the combustion controller is configured to control the second gas valve V2 to open, and the combustion controller controls the pilot fire ignition valve Pv to close after a certain delay, and the main fire is ignited successfully. If the combustion controller does not receive a rectifier signal, the combustion controller controls the first gas valve V1 and the pilot fire ignition valve Pv to close, or the combustion controller controls the first gas valve V1 and the second gas valve V2 to close.

6. The double-furnace boiler combustion control system according to claim 5, characterized in that: If the combustion controller does not receive the rectification signal, the combustion controller controls the first gas valve V1 and the pilot fire ignition valve Pv to close, or the combustion controller controls the first gas valve V1 and the second gas valve V2 to close, then the ignition fails, and the combustion controller alarms and self-locks and saves the ignition failure record.

7. The dual-furnace boiler combustion control system according to claim 1, characterized in that: It also includes a shell, the double furnace is located in the shell, a heat exchange shell is arranged in the shell, a heat exchanger is arranged outside each combustion head, and two heat exchangers are arranged in the heat exchange shell.

8. The dual-furnace boiler combustion control system according to claim 1, characterized in that: The first flame detector and the second flame detector are both flame relays.

9. The dual-furnace boiler combustion control system according to claim 1, characterized in that: The combustion controller includes a flame detection contact, and the rectifier unit includes a capacitor, a resistor, a diode and a resistor. One end of the diode is connected to the flame detection contact, the other end of the diode is connected in series with one end of the resistor, the other end of the resistor is connected in series with the first flame detector and the second flame detector, and the capacitor is connected in parallel with the diode.

10. The double-furnace boiler combustion control system according to claim 1, characterized in that: The rectifier unit is also provided with a status indicator light and a test button.

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